This study was done to assess the morphological changes in peripheral blood smears during COVID-19 infection .We aimed to examine the characteristics of the cells detected in the peripheral blood smear and bone marrow at the time of diagnosis in COVID-19 patients. Clinical features, laboratory data, peripheral blood smear of 35patients diagnosed with COVID-19 by PCR was evaluated at diagnosis. Peripheral smear samples of the patients were compared with the age and sex-matched 35 healthy controls. The relationship between the laboratory values of all patients and the duration of hospitalization was analyzed. Peripheral smear shows neutrophilic leucocytosis, lymphopenia and thrombocytopenia while Bone marrows were normocellular to hypercellular, most showing maturing trilineage hematopoiesis with myeloid left shift. In 09 out of 35 evaluable bone marrows, hemophagocytic histiocytes were identified